// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/trace_event/trace_event_system_stats_monitor.h"

#include <sstream>
#include <string>

#include "base/macros.h"
#include "base/run_loop.h"
#include "base/trace_event/trace_event_impl.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace base {
namespace trace_event {

#if !defined(OS_IOS)
    // Tests for the system stats monitor.
    // Exists as a class so it can be a friend of TraceEventSystemStatsMonitor.
    class TraceSystemStatsMonitorTest : public testing::Test {
    public:
        TraceSystemStatsMonitorTest() { }
        ~TraceSystemStatsMonitorTest() override { }

    private:
        DISALLOW_COPY_AND_ASSIGN(TraceSystemStatsMonitorTest);
    };

    //////////////////////////////////////////////////////////////////////////////

    TEST_F(TraceSystemStatsMonitorTest, TraceEventSystemStatsMonitor)
    {
        MessageLoop message_loop;

        // Start with no observers of the TraceLog.
        EXPECT_EQ(0u, TraceLog::GetInstance()->GetObserverCountForTest());

        // Creating a system stats monitor adds it to the TraceLog observer list.
        std::unique_ptr<TraceEventSystemStatsMonitor> system_stats_monitor(
            new TraceEventSystemStatsMonitor(message_loop.task_runner()));
        EXPECT_EQ(1u, TraceLog::GetInstance()->GetObserverCountForTest());
        EXPECT_TRUE(
            TraceLog::GetInstance()->HasEnabledStateObserver(
                system_stats_monitor.get()));

        // By default the observer isn't dumping memory profiles.
        EXPECT_FALSE(system_stats_monitor->IsTimerRunningForTest());

        // Simulate enabling tracing.
        system_stats_monitor->StartProfiling();
        RunLoop().RunUntilIdle();
        EXPECT_TRUE(system_stats_monitor->IsTimerRunningForTest());

        // Simulate disabling tracing.
        system_stats_monitor->StopProfiling();
        RunLoop().RunUntilIdle();
        EXPECT_FALSE(system_stats_monitor->IsTimerRunningForTest());

        // Deleting the observer removes it from the TraceLog observer list.
        system_stats_monitor.reset();
        EXPECT_EQ(0u, TraceLog::GetInstance()->GetObserverCountForTest());
    }
#endif // !defined(OS_IOS)

} // namespace trace_event
} // namespace base
